London -LRB- CNN -RRB- -- Work on the world 's largest solar bridge has started in central London .

The new solar roof spanning Blackfriars Railway Bridge above the River Thames will cover more than 6,000 square meters when finished , according to developers .

Over 4,400 individual photovoltaic panels are expected to produce around 900,000 kilowatt hours of electricity every year , providing the station with half of its energy needs , according to Solar Century , the UK company installing the solar roof .

Annual CO2 emissions are also expected to be reduced by more than 500 tons .

`` It 's fantastic to see this project finally come to fruition . Blackfriars Bridge is an ideal location for solar , '' Derry Newman , chief executive of Solar Century , said in a statement .

`` For people to see that solar power is working is a vital step towards a clean energy future , '' he added .

Built in 1886 , the railway bridge is being transformed as part of an upgrade by Network Rail -- the owner and operator of rail infrastructure in the UK -- to the existing Blackfriars station .

`` The Victorian rail bridge at Blackfriars is part of our railway history . Constructed in the age of steam , we 're bringing it bang up to date with 21st century solar technology to create an iconic station for the city , '' Lindsay Vamplew , Network Rail 's project director for Blackfriars said in a statement .

In addition to the solar panels -LRB- manufactured by the SANYO Electric Co. Ltd -RRB- , the station will also include rain-harvesting systems and sun pipes for natural lighting .

The solar roof and the new station are due to be completed by the summer of 2012 .

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New solar array will be largest on a bridge anywhere in the world , say developers

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Blackfriars Railway Bridge in central London will carry 4,400 photovoltaic solar cells on roof

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PV panels will create 900,000 kilowatt hours of electricity per year , generating 50 % of new station 's power

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New station due for completion in 2012